It is Wednesday, September 29, 2021, 3:21 p.m. Hawai‘i Standard Time (HST). Abigail Nalesnik is finishing up her fieldwork for the day. The University of Delaware doctoral student had been collecting samples of volcanic rock along a gully west of the summit of Kīlauea — one of the most active volcanoes in the world — working alongside Kendra J. Lynn, geologist for the U.S. Geological Survey and an affiliated professor at UD.

Then the alert came.

“There was an earthquake swarm under the summit, although we hadn’t felt anything,” Nalesnik said. “As we began driving from my field site, we saw the smoke rising out of Halema‘uma‘u crater. It was an amazing first view of a volcanic plume!”

Witnessing a volcano erupt is an unforgettable experience. And Kīlauea — one of the world’s youngest volcanoes, known to Hawaiians as the home of the revered goddess Pelehonuamea (Pele) — has offered up this incredible spectacle with some frequency. At this rupture in Earth’s crust, lava and gas have exploded from a magma chamber below the surface dozens of times since 1952 like a giant pressure cooker blowing its top.

Within minutes after seeing the plume, the USGS team began deploying to the eruption site in a closed area of Hawai‘i Volcanoes National Park.

“We drove down an old portion of park road around the summit crater and began to study the fresh lava that had been thrown up and out of the crater,” Lynn said. “Now cooled, these freshly made rocks, ranging from a millimeter to 15 centimeters in diameter, were very vesicular – meaning they had a lot of gas bubbles – when they were quenched. These feather-light pumices were already rolling across the road and landscape, being buffeted about by the wind.”

ABOVE AUDIO: Sounds of lava lake activity within Kīlauea volcano’s summit vent inside Halema‘uma‘u crater on February 14, 2011. Courtesy U.S. Geological Survey. 

Lynn was impressed by the sound of the rocks and particles called tephra being ejected from the volcano.

“The rolling clasts made a light ‘tink, tink, tink’ that made me instantly think of Christmas ornaments. When the wind gusts died down, there was an incredible sloshing sound, like waves on a beach. This was the lava and the active eruption, which was out of sight deep in the crater beyond where we were working.”

Nalesnik will never forget the sound of the lava fountains.

“Somewhat like very heavy water splashing down onto the lava lake, but unlike anything I’ve heard before. You could hear the fountains without being very close to the edge of the crater.”

“Not fantastic,” Nalesnik said, due to the sulfur dioxide, which smells like burnt matches. What’s more, sulfur dioxide irritates the eyes, nose and throat, causing you to cough and have a tight feeling in the chest. Headache, nausea, fatigue are other effects. Thus, gas masks were necessary to be in the area. But the view more than made up for it.

“Arriving at the edge of the crater to do measurements, the glow of the lava lake was surreal, with each small fountain and bubble of lava a fiery orange-red.”

With the eruption occurring deep inside Halema‘uma‘u crater, the researchers monitored the event from a distance and were not close enough to sample the lava. Still, they could feel the heat due to the vast size of the lava lake — estimated to be 70 floors deep if the Empire State Building were plopped into it.

“You can feel the heat on your face, but it is surprisingly chilly at the summit with the strong winds,” Nalesnik said.

Each team member wears a respirator, a critical piece of personal protective equipment (PPE) that must be worn when sulfur dioxide is present, Lynn said. They also wear an electronic gas badge calibrated to vibrate and beep to signal the concentration levels of sulfur dioxide, so they can quickly get out of areas inundated with gas. Other essentials include high-visibility uniforms, hard hats, cotton pants (synthetic materials melt when close to an active lava field), sturdy leather boots, and when windy, goggles to protect the eyes from blowing ash.

Volcanoes are among Nature’s greatest wonders, but they also can be extremely dangerous. Kīlauea’s eruption in 2018 caused evacuations in residential areas southeast of Hawai‘i Volcanoes National Park, as fissures opened up in the Earth’s crust — some 22 of these long, narrow cracks — and the large flows of lava destroyed more than 700 homes, as well as roads, schools and businesses. For months, residents downwind had to wear N95 masks to protect themselves from toxic ash and sulfur dioxide gas.

The scientists at the Hawaiian Volcano Observatory (HVO) have wide-ranging skills for studying such an explosive phenomenon. As a field geologist, Lynn works with her team to monitor the eruption on site. In addition to a permanent network of time-lapse and networked cameras, they capture the volcanic activity with high-resolution photographs and videos. They also use a rangefinder to measure the height of the lava lake and other features in the crater, which helps them to make important calculations such as lava fountain heights and effusion rates, which might increase if an eruption is gaining intensity or decrease if an eruption is waning.

Lynn is also a petrologist — a scientist who studies the composition, texture and structure of rocks and minerals to understand how and when they formed — so she collects samples of tephra and olivine, a mineral rich in iron and manganese, for polishing and chemical analysis back in the lab. Olivine can provide clues as to when and where the magma was stored in the volcano prior to the eruption.

“I look for patterns in the chemistry of erupted lavas that might help us to understand how the volcano behaves over decades to centuries,” Lynn said. “This might give us a better idea of what to expect in the future and be better prepared for the hazards associated with such events. In general, our monitoring observations help assess hazards and risk in real time, and the information allows the National Park Service and other agencies to make decisions.”

“I was surprised at how much there is to do!” Nalesnik said. “There are various specialties at HVO, such as the gas team that measures the volcano emissions, the seismology team that monitors the earthquakes, and of course the geology team that studies the physical deposits. These and several other teams have so many different avenues for study and analyses that reflect on different aspects of the volcano. It was great to see them all working together to navigate this current eruption and learn all that we can.”

For Lynn, the sheer scale of Earth’s outburst never gets old.

“I am shocked every time I see an eruption at how big it is — that we can have fountains of lava over 60 feet tall — that’s taller than a four-story building!”

“Participating in an active eruption response was definitely #1 on my bucket list!” said Nalesnik, who had received funding from the National Science Foundation to do work at the site for her UD doctoral research under the guidance of her adviser, Professor Jessica Warren. “Driving from my field site, seeing the plume rising out of Halema‘uma‘u, feeling so excited and nervous, will be a memory I keep for the rest of my life. As volcanoes are such dynamic landforms, I am thankful I had my gear packed and was prepared in case something happened during my short visit. Five weeks isn’t a very long time.”

For Lynn, Kīlauea has always been a very special place. “Growing up, I dreamed of studying it, and when I finally got that opportunity in graduate school, visiting the volcano changed my life forever,” she said. “Kīlauea is my favorite place on Earth, and is also a special and sacred place in Hawaii, home to Pelehonuamea, goddess of the volcano. As a guest in Hawaii and at Kīlauea, I am constantly in awe of Pele.”